FIG. 1 illustrates a prior art dimmer switch that may be installed in a wall-mount electrical box and wired to control the flow of electricity to a lighting load. The dimmer switch includes a housing 10 that encloses a power switch and electronic circuitry to control the amount of power applied to the lighting load. A mounting plate 12 forms a front cover for the housing and positions the dimmer switch against a wall surface when it is mounted to an electrical box with mounting screws 14. A rocker switch actuator enables a user to set the dimming level of the lighting load. Pressing the right side 16 of the actuator increases the dimming level, while pressing the left side 18 decreases the dimming level. A viewing lens 20 channels light from a row of indicator lights inside the dimmer switch that indicate the dimming level. A paddle switch actuator 22 turns the load completely off with one push, and turns the load back on to the previous dimming level with a second push. A locator light feature 24 illuminates when the load is off to enable a user to locate the dimmer switch in a darkened room.
Referring to FIG. 2, the visible components of the dimmer switch of FIG. 1 may be implemented as a color change kit 26 to enable the color of the dimmer switch to be changed in response to changes in decorating, or to replace damaged or worn-out components. The color change kit 26 includes a frame 28 in which the paddle 22 is pivotally mounted. The frame 28 includes compressible snaps 30 that engage with openings 32 on the mounting plate 12 to enable the color change kit to be removed and installed without tools.
FIG. 3 is a cross-sectional view of the viewing lens 20, along with a light pipe system that enables light from indicator lights deep inside the dimming switch to be channeled to a user. Each of seven indicator lights 34 is implemented as a light emitting diode (LED) mounted on a circuit board 36. Light from each LED is channeled through one of seven light pipes 38. Light from an LED travels the length of a light pipe and emerges at the other end. The emerging light 40 travels across a short gap 42 between the light pipe and viewing lens 22, where it enters a corresponding tooth 44 that admits the light into the viewing lens. The geometry and configuration of the components guides the light through the viewing lens in a manner that produces a light pattern 46, and corresponding viewing angle, that is typically less than about 35 degrees.
The viewing lens is made separate from the light pipes to accommodate changes in the length of the gap 42 as the paddle switch is depressed as shown by arrow 43, and to accommodate removing the color change kit, which includes the viewing lens. Though not shown in FIG. 3, light separators are typically included between the individual light pipes 38.
Referring to FIG. 4, the dimmer switch may be implemented with a flip-up paddle design that enables the paddle to pivot to an extended position as shown by arrow 48. Placing the paddle in the extended position may be useful to actuate an air gap switch or to allow access to additional controls that may be located under the paddle. For example, an electronic dimmer switch typically uses a solid state switch to turn the load on and off, and to control the dimming level of the load. There are situations, however, when a solid state switch allows unacceptable leakage current to flow, e.g., when replacing a burned out lamp. Therefore, the paddle may be configured to actuate a microswitch when placed in the extended position. The microswitch provides an air gap opening in the circuit, thereby eliminating leakage current.
To support the paddle in the extended position, the dimming switch includes two support mechanisms 50. FIG. 5 is a cross-sectional view of the support mechanisms 50 shown looking in the direction of arrows A-A in FIG. 4. Each mechanism 50 includes a resilient latch 52 attached to the paddle 22. When the paddle is in the retracted position, i.e., close to the mounting plate of the dimming switch, as shown in FIG. 5, each of the latches is engaged with a projection 54 on a corresponding rigid support member 56. This holds the paddle in the retracted position.
If a user attempts to move the paddle to the extended position, there is initial resistance cause by the enlarged portions of the latches 52 engaging against the projections 54. However, as the amount of force applied to the paddle increases, the resilient latches 52 begin to deflect as shown in FIG. 6. This enables the paddle to move upward as the latches move past the projections 54. When the paddle reaches the fully extended position, as shown in FIG. 7, the resilient latches spring back to their normal position and engage the top of the projections 54. The paddle is thus supported in the extended position until the user pushes down on the paddle with enough force to flex the resilient latches and return them to the latched position as shown in FIG. 5.